<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>float</title>
    <style type="text/css">
     #div1, #div2,#div3{
         width: 200px;
         height: 200px;
         background-color: #4E6B33;
         float: left;
     }
     #div2{
         background-color: #026E93;
         clear: both;

     }
     #div3{
         background-color: #999999;
     }
    </style>
</head>
<body>
<div id="div1"></div>
<div id="div2"></div>
<div id="div3"></div>
</body>
</html>